How do I made this screw tube not have an invisible wall?
The reason your simulation isn't working as expected is because the tube has a screw modifier on it that hasn't been applied. 

Apply the modifier to make the geometry real, and it will work just fine. You also should apply tranforms with Ctrl+A rotation and scale (in object mode) on  all objects involved in the simulation. Otherwise the simulation can become unstable and have unexpected results.